This week, the Eclipse Foundation will celebrate its most significant release to date, Callisto, an update that incorporates 10 linked projects in the IDE. Partners say the release is a major milestone on Eclipse's path to becoming the IT industry's de facto Java development platform.

"There was latency between releases that we needed to address," said Ian Skerrett, director of marketing for the Eclipse Foundation, in explaining Callisto's impetus. "If we can be on this predictable heartbeat of release, then people can do their planning a lot more easily about how they incorporate Eclipse."

In the four years since IBM turned the foundational technology for Eclipse over to an open-source, independent governance organization, the Eclipse IDE has become so popular it has raced to the head of the field in the Java IDE market. Evangelists and development contributors say Eclipse's strength is its flexibility and its governing board's choice to make the platform vendor-friendly.

"We like the philosophy behind Eclipse," said Nobby Akiha, vice president of marketing at Actuate, a South San Francisco, Calif., maker of reporting software. "It ties an open-source foundation with the recognition that [participants] need a commercial offering."

Actuate leads the management committee for Eclipse's Business Intelligence and Reporting Tools Project (BIRT) project, one of 10 that has synchronized on the Callisto release schedule. Actuate pursues a hybrid business model with BIRT, offering the core technology for free as part of the open-source Eclipse platform while selling a separate enterprise version with more advanced functionality, support services and indemnification.

Sun Microsystems, Santa Clara, Calif., remains an Eclipse holdout and continues to develop its own rival, NetBeans Java IDE, but most of Eclipse's other competitors have conceded the market and refashioned their strategies around Eclipse.

Borland Software, in the process of selling off the IDE business that was once its cornerstone, shifted its JBuilder IDE to an Eclipse base last year. "Eclipse is increasingly popular and impossible to ignore," said Richard Gronback, chief scientist at Borland, Cupertino, Calif.

ISVs say Callisto is a key step forward in Eclipse's evolution. For the first time, a batch of Eclipse projects have synchronized their release schedule with the core Eclipse platform's annual June update, allowing developers to field updates all at once rather than piecemeal.

"One of the historical problems with Eclipse has been that each of the independent projects releases on its own schedule," said Tim Lang, vice president of developer programs at Business Objects. "From a software vendor perspective, that's very hard to QA your products against."

The San Jose, Calif.-based ISV is taking advantage of the Callisto schedule to time the release of its Crystal Reports for Eclipse plug-in. That offering, a rival to Actuate's BIRT, will ship a few weeks after Callisto's June 30 release, but pricing has not yet been disclosed.

Callisto participants say the synchronized development cycle went remarkably smoothly. "When we first started, [Eclipse Executive Director] Mike Milinkovich and I were thinking, 'We've never done this before, and we're doing it very publicly.' There was a real risk," said Eclipse's Skerrett. "I was convinced that one or two [projects] would drop out, but none have."

Instead, Callisto has picked up a few shadow projects—Eclipse initiatives that weren't far enough along to opt into official Callisto participation, but still plan to time their updates to coincide with Callisto.

Mark Coggins, Actuate's senior vice president of engineering, said the Eclipse Foundation has come a long way since Actuate joined two years ago, when it occasionally ran into technical and bureaucratic snafus in its BIRT work. With Callisto, Eclipse has successfully coordinated a project that encompasses seven million lines of code and 260 code committers from a dozen countries, he said. "[Callisto] was a triumph of planning and a triumph of careful management."